#include <bits/stdc++.h>
using namespace std;


int main() {
    int q;
    cin>>q;
    while(q--)
        {
        int n,i;
        cin>>n;
        int pr[n][2];
        for(i=0;i<n;i++)
            cin>>pr[i][0]>>pr[i][1];
        int tl[2],ru[2],ld[2],dr[2];
        ld[0]=tl[0]=ru[0]=dr[0]=pr[0][0];
        ld[1]=tl[1]=ru[1]=dr[1]=pr[0][1];
        if(n<4)
            cout<<"YES\n";
        else
            {
        for(i=1;i<n;i++)
            {

            if(pr[i][0]<ld[0])
                {
                ld[0]=pr[i][0];
                ld[1]=pr[i][1];
            }
            else if(pr[i][0]==ld[0])
                {
                ld[1]=min(ld[1],pr[i][1]);
            }
            if(pr[i][1]>tl[1])
                {
                tl[0]=pr[i][0];
                tl[1]=pr[i][1];
            }
            else if(pr[i][1]==tl[1])
                {
                tl[0]=min(tl[0],pr[i][1]);
            }


            if(pr[i][0]>ru[0])
                {
                ru[0]=pr[i][0];
                ru[1]=pr[i][1];
            }
            else if(pr[i][0]==ru[0])
                {
                ru[1]=max(ru[1],pr[i][1]);
            }



            if(pr[i][1]<dr[1])
                {
                dr[0]=pr[i][0];
                dr[1]=pr[i][1];
            }
            else if(pr[i][1]==dr[1])
                {
                dr[0]=max(dr[0],pr[i][1]);
            }
        }
        /*cout<<tl[0]<<" "<<tl[1]<<endl;
        cout<<ld[0]<<" "<<ld[1]<<endl;
        cout<<ru[0]<<" "<<ru[1]<<endl;
        cout<<dr[0]<<" "<<dr[1]<<endl;*/
        for(i=0;i<n;i++)
            {
            if((pr[i][0]-ld[0])*(pr[i][0]-ld[0])+(pr[i][1]-ld[1])*(pr[i][1]-ld[1])+(pr[i][0]-tl[0])*(pr[i][0]-tl[0])+(pr[i][1]-tl[1])*(pr[i][1]-tl[1])==(tl[0]-ld[0])*(tl[0]-ld[0])+(tl[1]-ld[1])*(tl[1]-ld[1])||
              (pr[i][0]-ld[0])*(pr[i][0]-ld[0])+(pr[i][1]-ld[1])*(pr[i][1]-ld[1])+(pr[i][0]-dr[0])*(pr[i][0]-dr[0])+(pr[i][1]-dr[1])*(pr[i][1]-dr[1])==(dr[0]-ld[0])*(dr[0]-ld[0])+(dr[1]-ld[1])*(dr[1]-ld[1])||
              (pr[i][0]-ru[0])*(pr[i][0]-ru[0])+(pr[i][1]-ru[1])*(pr[i][1]-ru[1])+(pr[i][0]-tl[0])*(pr[i][0]-tl[0])+(pr[i][1]-tl[1])*(pr[i][1]-tl[1])==(tl[0]-ru[0])*(tl[0]-ru[0])+(tl[1]-ru[1])*(tl[1]-ru[1])||
              (pr[i][0]-ru[0])*(pr[i][0]-ru[0])+(pr[i][1]-ru[1])*(pr[i][1]-ru[1])+(pr[i][0]-dr[0])*(pr[i][0]-dr[0])+(pr[i][1]-dr[1])*(pr[i][1]-dr[1])==(dr[0]-ru[0])*(dr[0]-ru[0])+(dr[1]-ru[1])*(dr[1]-ru[1]))
                {

            }
            else break;
        }
        if(i<n)
            cout<<"NO\n";
        else cout<<"YES\n";
        }
    }
    return 0;
}